Added -index special variable.

src/main/java/com/samskivert/mustache/Mustache.java

@@ -387,12 +387,16 @@ public class Mustache
                 return; // TODO: configurable behavior on missing values
             }
             if (value instanceof Iterable<?>) {
+                value = ((Iterable<?>)value).iterator();
+            }
+            if (value instanceof Iterator<?>) {
                 Template.Mode mode = null;
-                for (Iterator<?> iter = ((Iterable<?>)value).iterator(); iter.hasNext(); ) {
+                int index = 0;
+                for (Iterator<?> iter = (Iterator<?>)value; iter.hasNext(); ) {
                     Object elem = iter.next();
                     mode = (mode == null) ? Template.Mode.FIRST :
                         (iter.hasNext() ? Template.Mode.OTHER : Template.Mode.LAST);
-                    executeSegs(tmpl, ctx.nest(elem, mode), out);
+                    executeSegs(tmpl, ctx.nest(elem, ++index, mode), out);
                 }
             } else if (value instanceof Boolean) {
                 if ((Boolean)value) {
@@ -402,18 +406,10 @@ public class Mustache
                 for (int ii = 0, ll = Array.getLength(value); ii < ll; ii++) {
                     Template.Mode mode = (ii == 0) ? Template.Mode.FIRST :
                         ((ii == ll-1) ? Template.Mode.LAST : Template.Mode.OTHER);
-                    executeSegs(tmpl, ctx.nest(Array.get(value, ii), mode), out);
-                }
-            } else if (value instanceof Iterator<?>) {
-                Template.Mode mode = null;
-                for (Iterator<?> iter = (Iterator<?>)value; iter.hasNext(); ) {
-                    Object elem = iter.next();
-                    mode = (mode == null) ? Template.Mode.FIRST :
-                        (iter.hasNext() ? Template.Mode.OTHER : Template.Mode.LAST);
-                    executeSegs(tmpl, ctx.nest(elem, mode), out);
+                    executeSegs(tmpl, ctx.nest(Array.get(value, ii), ii+1, mode), out);
                 }
             } else {
-                executeSegs(tmpl, ctx.nest(value, Template.Mode.OTHER), out);
+                executeSegs(tmpl, ctx.nest(value, 0, Template.Mode.OTHER), out);
             }
         }
     }

src/main/java/com/samskivert/mustache/Template.java

@@ -42,7 +42,7 @@ public class Template
      */
     public void execute (Object context, Writer out) throws MustacheException
     {
-        Context ctx = new Context(context, null, Mode.OTHER);
+        Context ctx = new Context(context, null, 0, Mode.OTHER);
         for (Segment seg : _segs) {
             seg.execute(this, ctx, out);
         }
@@ -100,6 +100,8 @@ public class Template
             return ctx.mode == Mode.FIRST;
         } else if (name == LAST_NAME) {
             return ctx.mode == Mode.LAST;
+        } else if (name == INDEX_NAME) {
+            return ctx.index;
         }
 
         while (ctx != null) {
@@ -242,16 +244,18 @@ public class Template
     {
         public final Object data;
         public final Context parent;
+        public final int index;
         public final Mode mode;
 
-        public Context (Object data, Context parent, Mode mode) {
+        public Context (Object data, Context parent, int index, Mode mode) {
             this.data = data;
             this.parent = parent;
+            this.index = index;
             this.mode = mode;
         }
 
-        public Context nest (Object data, Mode mode) {
-            return new Context(data, this, mode);
+        public Context nest (Object data, int index, Mode mode) {
+            return new Context(data, this, index, mode);
         }
     }
 
@@ -309,4 +313,5 @@ public class Template
     protected static final String THIS_NAME = "this".intern();
     protected static final String FIRST_NAME = "-first".intern();
     protected static final String LAST_NAME = "-last".intern();
+    protected static final String INDEX_NAME = "-index".intern();
 }

src/test/java/com/samskivert/mustache/MustacheTest.java

@@ -188,6 +188,11 @@ public class MustacheTest
              context("things", Arrays.asList("foo", "bar", "baz")));
     }
 
+    @Test public void testIndex () {
+        test("123", "{{#things}}{{-index}}{{/things}}",
+             context("things", Arrays.asList("foo", "bar", "baz")));
+    }
+
     protected void test (String expected, String template, Object ctx)
     {
         assertEquals(expected, Mustache.compiler().compile(template).execute(ctx));